
function stack_ (n){
    var  arr = [1]
    var length = 0
    var n = n;
}
stack_.prototype.push_ = function(node){
    this.arr[Math.floor(this.length/this.n)] = 1
    this.length++ 
}
stack_.prototype.pop_ = function(){
    if(length<0){
        throw 'error'
    }else{
        this.arr[length] = null
        this.length--
    }
}

var stack1 =new stack_(3)
console.log(stack1.arr);
